A sucker rod load reducing device

Abstract

An oil sucker rod load reducing device, the pump diameter of the upper pump cylinder is smaller than that of the lower pump cylinder, the upper pump cylinder, the different-diameter pump cylinder joint and the lower pump cylinder are connected in sequence, the lower part of the upper hollow piston rod is connected with the upper thread of the different-diameter piston joint, the lower thread of the different-diameter piston joint is connected with the upper part of the hollow connecting rod, the upper part of the lower hollow piston is connected with the middle thread of the different-diameter piston joint, the inner wall of the lower hollow piston and the outer wall of the hollow connecting rod form a flow passage due to the diameter difference, the upper hollow piston rod penetrates into the upper pump cylinder, the lower hollow piston is in the lower pump cylinder, the upper hollow piston rod and the inner wall of the lower pump cylinder form a breathing cavity due to the diameter difference, the upper part of the upper hollow piston rod has a sucker rod joint, the different-diameter piston joint has a lateral groove and a vertical passage, a blind hole is drilled upward on the lower end face of the different-diameter piston joint, the sucker rod joint has a connecting groove, the influence of casing pressure on the load reducing effect is eliminated, the load of the sucker rod above the installation position can be reduced, and thick oil can be exploited by matching casing thinning and viscosity reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to an oil pumping device for oil field, in particular to a sucker rod load reducing device. BACKGROUND

[0002] The reciprocating rod pump oil pumping device for oil field comprises an oil pumping unit, a sucker rod, an oil pumping pump and a tubing, the oil pumping unit is installed on the ground, the sucker rod, the oil pumping pump and the tubing are installed in the wellbore of the oil well, the oil pumping unit drives the oil pumping pump to reciprocate to pump the crude oil in the well to the ground through the sucker rod. In the reciprocating rod pump oil pumping in the deep well and the super deep well, the load borne by the oil pumping unit and the sucker rod is large.

[0003] Therefore, the technical personnel has researched the sucker rod load reducing device, which is installed on the tubing and the sucker rod between the wellhead and the oil pumping pump to reduce the load borne by the sucker rod above the installation position and the load borne by the oil pumping unit. The sucker rod load reducing device utilizes the pressure difference between the tubing and the casing at the installation position to generate the load reducing effect, and the load reducing effect is influenced by the casing pressure, when the casing liquid level is high, the load reducing effect is poor, for example, when the casing pressure is at the wellhead (the casing is mixed with the thin liquid, which will cause the problem), the load reducing effect is not generated. SUMMARY

[0004] The purpose of the present application is to design a sucker rod load reducing device to eliminate the influence of the casing pressure on the load reducing effect and reduce the load borne by the sucker rod above the installation position.

[0005] The purpose of the present application is achieved by the following technical scheme: the sucker rod load reducing device comprises an upper hollow piston rod, an upper pump barrel, a reducer pump barrel joint, a reducer piston joint, a lower hollow piston, a lower pump barrel and a hollow connecting rod, the pump diameter of the upper pump barrel is smaller than the pump diameter of the lower pump barrel, the upper pump barrel, the reducer pump barrel joint and the lower pump barrel are connected in sequence, the lower part of the upper hollow piston rod is connected with the upper thread of the reducer piston joint, the lower thread of the reducer piston joint is connected with the upper part of the hollow connecting rod, the upper part of the lower hollow piston is connected with the middle thread of the reducer piston joint, the over-flow passage is formed between the inner wall of the lower hollow piston and the outer wall of the hollow connecting rod due to the diameter difference, the upper hollow piston rod penetrates into the upper pump barrel, the lower hollow piston is in the lower pump barrel, the breathing cavity is formed between the upper hollow piston rod and the inner wall of the lower pump barrel due to the diameter difference, the upper part of the upper hollow piston rod is provided with a sucker rod joint, the upper hollow piston rod is sealed with the upper pump barrel, the lower hollow piston is sealed with the lower pump barrel, the reducer piston joint is provided with a lateral groove and a vertical passage, a blind hole is drilled upward at the lower end face of the reducer piston joint, the upper part of the blind hole is communicated with the lateral groove, the inner hole of the hollow connecting rod is communicated with the breathing cavity, the upper part of the over-flow passage is communicated with the lower end of the vertical passage, the upper end of the vertical passage is communicated with the center hole of the upper hollow piston rod, the sucker rod joint is provided with a communication groove, and the communication groove makes the center hole of the upper hollow piston rod communicated with the outside.

[0006] The beneficial effects of this invention are as follows: When used in conjunction with a hollow oil pump, the inlet pressure of the hollow oil pump is almost zero during operation. The upper end face of the lower hollow piston is connected to the inlet of the hollow oil pump, eliminating the influence of casing pressure on its load reduction effect. Even when the casing pressure is high and the casing is diluted to reduce viscosity, a large upward thrust can be generated at the installation point of this invention, reducing the load on the sucker rod above this invention. It can be used in conjunction with the dilution and viscosity reduction process on the casing pump to extract heavy oil. Attached Figure Description

[0007] Figure 1 This is an assembly diagram of an embodiment of the present invention. Implementation

[0008] The following is combined with Figure 1 Embodiments of the present invention will be described.

[0009] like Figure 1 As shown, an embodiment of the present invention includes an upper hollow piston rod 2, an upper pump cylinder 3, a reducing pump cylinder connector 4, a reducing piston flow divider 5, a lower hollow piston 6, a lower pump cylinder 7, and a hollow connecting rod 8. The pump diameter of the upper pump cylinder 3 is smaller than that of the lower pump cylinder 7. The upper pump cylinder 3, the reducing pump cylinder connector 4, and the lower pump cylinder 7 are connected sequentially. The lower part of the upper hollow piston rod 2 is connected to the upper thread of the reducing piston connector 5, the lower thread of the reducing piston connector 5 is connected to the upper part of the hollow connecting rod 8, and the upper part of the lower hollow piston 6 is connected to the middle thread of the reducing piston connector 5. A flow channel 6-1 is formed between the inner wall of the lower hollow piston 6 and the outer wall of the hollow connecting rod 8 due to the diameter difference. The upper hollow piston rod 2 is inserted into the upper pump cylinder 3, and the lower hollow piston 6 is located in the lower pump cylinder 7. The flow channel 6-1 between the inner wall of the upper hollow piston rod 2 and the inner wall of the lower pump cylinder 7 is formed by the diameter difference between the two components. The diameter difference forms a breathing chamber 7-1. The upper part of the upper hollow piston rod 2 has a sucker rod connector 1. The upper hollow piston rod 2 is sealed with the upper pump barrel 3. The lower hollow piston 6 is sealed with the lower pump barrel 7. The reducing piston connector 5 has a side groove 5-1 and a vertical channel 5-3. A blind hole 5-2 is drilled upward on the lower end face of the reducing piston connector 5. The upper part of the blind hole 5-2 communicates with the side groove 5-1, so that the inner hole of the hollow connecting rod 8 is connected to the breathing chamber 7-1. The upper part of the flow channel 6-1 is connected to the lower end of the vertical channel 5-3. The upper end of the vertical channel 5-3 is connected to the center hole of the upper hollow piston rod 2. The sucker rod connector 1 has a connecting groove 1-1. The connecting groove 1-1 connects the center hole of the upper hollow piston rod 2 to the outside.

[0010] The application is installed in the middle area of the oil pumping pipe column and is used in cooperation with the hollow oil pumping pump.

[0011] The communication groove 1-1, the central hole of the upper hollow piston rod 2, the vertical flow channel 5-3 and the flow passage 6-1 are liquid outlet channels, and well fluid is discharged from the communication groove 1-1 to the wellhead after being pressurized by the hollow oil pumping pump.

[0012] When the thickened oil well implements the dilution process, the diluted thin oil fills the casing, and a large liquid column pressure is formed in the casing. For the application, the liquid column pressure formed by the diluted thin oil in the casing does not act on the upper end surface of the lower hollow piston 6, and the pressure of the upper end surface of the lower hollow piston 6 is still substantially zero. Therefore, the application does not affect the load reduction effect when the casing is diluted and the thickened oil is pumped.

[0013] When the application and the hollow oil pumping pump are both installed in the middle area of the oil pumping pipe column, the upper end surface of the lower hollow piston 6 is communicated with the inlet of the hollow oil pumping pump through the central tube of the hollow oil pumping pump, so that the lost circulation liquid generated between the upper pump cylinder 3 and the upper hollow piston rod 2 and between the lower hollow piston 6 and the lower pump cylinder 7 flows back to the inlet of the hollow oil pumping pump and is recovered by the hollow oil pumping pump. Therefore, the application eliminates the disadvantage of the existing oil pumping rod load reduction device that the yield is lost, and can improve the yield of the oil well.

[0014] The structure of the hollow oil pumping pump is as disclosed in the electric heating thickened oil pumping pump in SY / T 7083-2016, and the structure of the hollow oil pumping pump has various types, and the hollow oil pumping pump with a full bore or a non-full bore and having a central channel and a circulating oil pumping channel can be used in cooperation with the application.

[0015] The cooperation sealing between the piston (rod) and the pump cylinder refers to the requirement specified in the GB / T 17607 standard. The pump diameter refers to the inner diameter of the pump cylinder of the oil pumping pump.

Claims

1. A sucker rod unloading device, characterized in that: The system includes an upper hollow piston rod (2), an upper pump cylinder (3), a reducing pump cylinder connector (4), a reducing piston connector (5), a lower hollow piston (6), a lower pump cylinder (7), and a hollow connecting rod (8). The pump diameter of the upper pump cylinder (3) is smaller than that of the lower pump cylinder (7). The upper pump cylinder (3), the reducing pump cylinder connector (4), and the lower pump cylinder (7) are connected in sequence. The lower part of the upper hollow piston rod (2) is connected to the upper thread of the reducing piston connector (5), the lower thread of the reducing piston connector (5) is connected to the upper part of the hollow connecting rod (8), and the upper part of the lower hollow piston (6) is connected to the middle thread of the reducing piston connector (5). A flow passage (6-1) is formed between the inner wall of the hollow piston (6) and the outer wall of the hollow connecting rod (8) due to the diameter difference. The upper hollow piston rod (2) is inserted into the upper pump barrel (3), and the lower hollow piston (6) is located in the lower pump barrel (7). A breathing chamber (7-1) is formed between the inner walls of the upper hollow piston rod (2) and the lower pump barrel (7) due to the diameter difference between the two. There is a sucker rod joint (1) at the upper part of the upper hollow piston rod (2). The upper hollow piston rod (2) and the upper pump barrel (3) are sealed together. The lower hollow piston (6) and the lower pump barrel (7) are sealed together. The reducing piston joint (5) has a side groove (5-1) and a vertical passage. A blind hole (5-2) is drilled upward on the lower end face of the reducing piston joint (5). The upper part of the blind hole (5-2) communicates with the side groove (5-1), so that the inner hole of the hollow connecting rod (8) communicates with the breathing chamber (7-1). The upper part of the flow passage (6-1) communicates with the lower end of the vertical channel (5-3). The upper end of the vertical channel (5-3) communicates with the center hole of the upper hollow piston rod (2). There is a connecting groove (1-1) on the sucker rod joint (1). The connecting groove (1-1) connects the center hole of the upper hollow piston rod (2) with the outer... The hollow connecting rod (8) is connected to the inlet of the hollow oil pump through the central tube on the hollow oil pump. Under the operation of the hollow oil pump, the pressure on the upper end face of the lower hollow piston (6) is basically zero. When the sucker rod unloading device and the hollow oil pump are both installed in the middle area of ​​the sucker string, the upper end face of the lower hollow piston (6) is connected to the inlet of the hollow oil pump through the central tube on the hollow oil pump, so that the leakage fluid generated by the gap between the upper pump barrel (3) and the upper hollow piston rod (2), and the lower hollow piston (6) and the lower pump barrel (7) flows back to the inlet of the hollow oil pump and is recovered by the hollow oil pump.

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